2500 4x2 Pickup V8-318 5.2L Magnum (1994)
Camshaft Position Sensor: Description and Operation
LOCATION
The Camshaft Position (CMP) Sensor is located in the distributor housing under the ignition rotor and pulse ring.
PURPOSE
The signal from the Camshaft Position (CMP) Sensor combined with the input signal from the Crankshaft Position (CKP) Sensor, are what the
Powertrain Control Module (PCM) uses to properly synchronize fuel injection.
OPERATION
Camshaft Position Sensor
The CMP Sensor is used to reference firing cylinders, it sends voltage to the PCM and works in conjunction with the CKP sensor so that the PCM
can establish and maintain the correct injector firing order.
The camshaft position sensor uses a 180° pulse ring on the end of the distributor shaft. The leading edge of the 180° pulse ring indicates that
number 1 cylinder is nearing Top Dead Center (TDC). The trailing edge of the pulse ring indicates that the number 6 cylinder is nearing TDC.
The CMP sensor generates a high/low voltage signal, as the pulse ring passes a hall effect switch. When the pulse ring passes in front of the hall
effect switch, a 5 volt signal is sent to the PCM. When a slot is not present, the PCM receives a 0.3 volt signal.
If PCM does not sense input from cam position sensor, PCM will deactivate ASD and fuel pump relays, interrupting voltage to fuel pump, fuel
injectors, and ignition coil, causing a no start condition.
